Издательство: "Wiley-Blackwell Publishing"
| Название: | Genetic structure, morphological variation, and gametogenic peculiarities in water frogs (Pelophylax) from northeastern European Russia | 
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| Автор ПГУ: | Спартак Николаевич  Антон Олегович Ермаков Олег Александрович | |
| Тематика: | биология | |
| Вид ресурса: | электронная копия бумажного издания | |
| Тип ресурса: | Статья | |
| Целевое назначение: | Научное | |
| Целевая аудитория: | Исследователь | |
| Аннотация: | The edible frog, Pelophylax esculentus, is a hybrid form that reproduces via clonal propagation of only one of the parental genomes through generations of hybrids while the genome of other parental species is eliminated during gametogenesis. Such reproductive ability requires hybrids to coexist with one of the parental species or rarely both parental species causing the formation of so-called population systems. Population systems and reproductive biology of water frogs from the east of the range remained partially unexplored. In this study, we investigated the distributions, population systems, genetic structure, types of gametes, and morphological variability of water frogs of the genus Pelophylax from the northeastern parts of their ranges (Mari El Republic and adjacent territories, Russia). We examined 1,337 individuals from 68 localities using morphological traits combined with DNA flow cytometry and a multilocus approach (fragments of a nuclear and two mitochondrial genes). We revealed five types of population systems: “pure” populations of the parental P. ridibundus (R) and P. lessonae (L), mixed populations of parental species (R-L) along and with their hybrids (R-E-L), as well as mixed populations of P. lessonae and P. esculentus (L-E). However, the “pure” hybrid (E) and the mixed P. ridibundus and P. esculentus (R-E) population systems were not found. All hybrids studied by DNA flow cytometry were diploid. Analysis of gametogenesis showed that the majority of hybrid males, as well as hybrid females from the L-E system, produced gametes with the P. ridibundus genome. However, in the R-E-L system, hybrid females were usually sterile. The reproduction of hybrids in such systems is primarily based on crosses of P. esculentus males with P. lessonae females. Molecular analysis showed the presence of mitochondrial and nuclear DNA introgression of the Anatolian marsh frog (P. cf. bedriagae) into both P. ridibundus and P. esculentus. The observations of alleles and haplotypes of P. cf. bedriagae in P. ridibundus and P. esculentus individuals from the same localities suggest de novo formation of local hybrids. However, the presence of the Balkan marsh frog (P. kurtmuelleri) haplotypes in local hybrids supports the hypothesis regarding the migration of old hemiclonal lineages from glacial refugia. Finally, the diagnostic value of various morphological characteristics was discussed. | |
| Дата издания: | 2021 | |
| Дата загрузки: | 28.09.2021 | |
| Название: | Holocene vegetation and hydroclimate changes in the Kansk forest steppe, Yenisei River Basin, East Siberia |
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| Автор ПГУ: | Стойко Тамара Григорьевна | |
| Тематика: | биология | |
| Вид ресурса: | электронная копия бумажного издания | |
| Тип ресурса: | Статья | |
| Целевое назначение: | Научное | |
| Целевая аудитория: | Исследователь | |
| Дата издания: | 2021 | |
| Дата загрузки: | 09.11.2021 | |
| Название: | Lack of genome elimination in adult hybrid males of the European water frog complex |
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| Автор ПГУ: | Ермаков Олег Александрович | |
| Тематика: | биология | |
| Вид ресурса: | электронная копия бумажного издания | |
| Тип ресурса: | Статья | |
| Целевое назначение: | Научное | |
| Целевая аудитория: | Исследователь | |
| Аннотация: | Sexual reproduction is a hallmark of most eukaryotes, yet hybridization can lead to alternative reproductive strategies, such as hybridogenesis. During hybridogenesis, found in the European water frog (Pelophylax esculentus) complex, one of the parental genomes is eliminated during gametogenesis, and the other one propagates clonally to gametes. We analyzed diploid hybrid males from populations common for hybrids and Pelophylax lessonae (L-E systems) from the eastern part of their distribution range. All but one hybrid produced spermatocytes and spermatids with Pelophylax ridibundus chromosomes, suggesting premeiotic elimination of P. lessonae genome and endoreplication of the P. ridibundus genome. We also observed spermatocytes with 13 or 26 univalents, indicating alterations in genome elimination and endoreplication. By comparing spermatocytes with germ cell genome composition, we suggest that genome elimination and endoreplication do not occur in adult males. Further, we examined introgressions using mitochondrial and nuclear genetic markers and comparative genomic hybridization. Most hybrids carried P. ridibundus and P. lessonae haplogroups, but five had Pelophylax cf. bedriagae mitochondrial DNA. In one hybrid, we revealed introgression of P. ridibundus chromosomal segments on P. lessonae chromosome. Although L-E systems are generally considered as stable, our results indicate variability in hybrid male gametogenesis, which may be related to introgressive hybridization. | |
| Дата издания: | 2026 | |
| Дата загрузки: | 12.10.2026 | |
| Название: | Nonlinearizable solutions in an eigenvalue problem for Maxwell's equations with nonhomogeneous nonlinear permittivity in a layer |
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| Автор ПГУ: | Валовик Дмитрий Викторович Тихов Станислав Вячеславович | |
| Тематика: | физико-математические науки | |
| Вид ресурса: | электронное немультимедийное издание | |
| Тип ресурса: | Статья | |
| Целевое назначение: | Научное | |
| Целевая аудитория: | Исследователь | |
| Дата издания: | 2022 | |
| Дата загрузки: | 07.11.2022 | |